Piston-valve



(No Model.) A H .f-WH'ITING'.

1 PISTQN VALVET lNo. 292,718. Patented Jail. 29, 1884.

Uivrrnn rnfrns Partnr @trice HENRY wHiriNo, or cnoirn harms, iowg-i.

PISTON-VALVE.

SPECIFICATION forming part of Letters Patent No. 292,778, dated January29, 18E4.

Application tiled July 30,1883. (No model.)

ing the same with separate .and independent.

valves in separate compartments of the steamehest-the one a variablecut-ofiI valve to regu late the flow of steam into the cylinder, and theother a valve to control the exhaust-steam v and permit a free escape ofthe same regardless of the quantity or pressure due to variations in thecut-off The invention consists in asteamchest provided with two chambersseparated by an intermediate diaphragm and opening into a commoninduction and eduction port at each end, communicating with the cylinderof the engine to which such vsteam-chest is attached, or of which itforms a part, and in two valves operating alternately in said chambers,the upper one being` the induction-valve, actuated by an automaticcut-off, and the lower one b'eing the exhaustlvalve actuated by regularand positive motion. i.

In the accompanying drawings, Figure I represents an end view of acylinder and steam-chest with piston and'valves in position; Fig'. 2, asectional side elevation of the steam-chest and valves.

rlhe device is of the simplest nature, as will be seen from the drawingsandthe description lfollowing. The cylinder is in the ordinary form,with straight ports at each end. To the side is attached or cast thesteam-chest A. This is divided into two compartments by a longitudinaldiaphragm, a. Both chambers communicate with transverse ports B B,corresponding to the ports in the cylinder. It is desirable to havethese ports continuous from top to bottom of the steam-chest andthroughl the diaphragm, for reasons that will be apparent by referringto the drawings. Both the steamchamber and the exhaust-chamber openinginto these ports, each has the advantage of a port as long as the widthof the steam-chest, and ordinarily the diameter of the cylinder.Consequently the vsteam has a better oppor-i tunity to iiow freely andquickly `from the steam-chamber into the cylinder, and from the cylinderinto the exhaust-chamber, than if such chambers communicated with thecylinder by separate ports. In the upper chamber is iitted the feed orinduction valve C, adapted to beoperated by automatic mechanismconnected to the main shaft, and governing the flow of steam to thecylinder by the speed of its revolutions in any suitable and well-knownmanner. Below it, in the other chamber, is a similar valve, G,toregulate the exhaust-steam,

and is actuated alternately with the upper valve by an eccentric orother mechanism attached to the main shaft, aiid adapted to impart to ita regular and positive stroke. The

relative position` of thevalves is shown in Fig. 2, where the cylinderis taking steam through the right-hand port and exhausting through theleft. The valves shown are simplepistonvalves, and are best adapted tothe invention, because they are the most easily tted up, as wel] as thevalve-seats, and whenconstructed as shown make perfectly-balancedvalves.

By using a'separate Fvalve for the exhaust I am able to afford free exitfor the dead steam,77 and avoid the compression7 due to a narrow port.Vhen but one valve is used regulated by a variable cut-off, it-'will beapparent that when the engine is running light the opening of the portswill be correspondingly small, and as a result the exhaust will beretarded and the compression of the escaping steam will becorrespondingly great. I

desire to make the exhaust perfectly uniform eline is given it towardthe center, where the i exhaust-pipe F is placed. rIhe object of this isto allow the water caused by condensation in the cylinder to iiowoutthrough the exhaustpi-pe, and thus avoid the necessity of providing thecylinder with cocks for that purpose.

IOO

I am aware that the use of two valves in a double-chambered steam'chestis not broadly new, and I do not claim such as my invention; but I amnot aware that any such steam-chest has been heretofore provided with asingle continuous port into which both chambers communicate, nor thatthe How of steam to and from the cylinder has ever been regulated byalternating balanced piston-valves, one actuated by an automatic cut-ofiand the other byindependent and regular motion, as hereinbei'oredescribed.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

l. The combination of a steam-engine cylinder, a stean1-chest having twochambers communicating` with a common port at each end, and balanceddouble-headed valves C C, applied in said chambers, and adapted tooperate substantially as described.

2. A steam-chest provided with chambers separated by an intermediatediaphragm and opening` into a common induction and eduction portcommunicating with the cylinder of 25

